Heretofore, in equipment using a free-piston type Stirling cycle engine, a vibration absorbing unit for absorbing vibrations of the Stirling cycle engine itself (hereinafter referred to as internal vibrations) has been provided in the Stirling cycle engine itself. This vibration absorbing unit, however, cannot absorb the internal vibrations completely and therefore a suspension mechanism has been used for blocking the internal vibrations so as not to transmit the vibrations from the Stirling cycle engine incorporated in the equipment to other portions. As an equipment provided with this type of suspension mechanism for the Stirling cycle engine, the applicant of the present invention once filed a patent application for a refrigerator 100 including a suspension mechanism according to a general technology for supporting legs 104 provided in the Stirling cycle engine 102, as shown in FIG. 6, wherein the legs 104 are sandwiched by means of compression springs 106, 108 from an upper side and lower side of the Stirling cycle engine 102 in an axial direction thereof (Japanese patent application 2003-311859).
According to this suspension mechanism for the Stirling cycle engine, axial vibration components among the internal vibrations of the Stirling cycle engine can be sufficiently absorbed, so that the internal vibration components transmitted to the equipment in which the Stirling cycle engine is incorporated can be substantially decreased. There has been a problem, however, that vibration components in a direction intersecting with an axis of the Stirling cycle engine among the internal vibrations, which are caused by installation error or the like, could not be sufficiently reduced. Further, it has also been a problem that among vibrations caused by swinging or rocking that takes place when the equipment in which the Stirling cycle engine is incorporated is conveyed and moved (hereafter referred to as external vibrations), the vibration components in the direction intersecting with the axis of the Stirling cycle engine can not be sufficiently absorbed. This problem is attributed to the fact that since the compression springs are used in the suspension mechanism, when the Stirling cycle engine vibrates in the direction intersecting with the axis of the Stirling cycle engine, the compression springs extend and thus not only the compression springs fail to function so as to resist against the movement of the Stirling cycle engine but a guiding shaft parallel to the axial direction of the Stirling cycle engine needs to be provided in the center of the compression spring in order that the suspension mechanism operates normally, and thus the compression springs collide with the guiding shaft when the vibrations of the Stirling cycle engine occur in the direction intersecting with its axis.